Spark arrester



Feb. 28, 1956 MAlMAN 2,736,541

SPARK ARRESTER Filed Dec. 1, 1949 2 Sheets-Sheet 1 INVENTOR 2 )1 HERBERT MAIMAN ATTORNEY 1956 H. MAIMAN 2,736,541

SPARK ARRESTER Filed Dec. 1, 1949 2 Sheets-Sheet 2 FIG. 2.

@ INVENTOR HERBERT MAI MAN ATTORNEY United States Patent 6 SPARK ARRESTER Herbert Maiman, Bala-Cynwyd, Pa.

Application December 1, 1949, Serial No. 130,577

1 Claim. (Cl. 261-126) (Granted under Title 35, U. S. Code (1952), sec. 266) The present invention relates to. spark arresters and more particularly to spark arresters for use on vessels.

Garbage and refuse disposal on combatant vessels operating in enemy waters has presented numerous security problems. If garbage and refuse is dumped in the ocean, it remains afloat for long periods of time and attracts seagulls, both of which provide visible evidence of the presence of a ship. If it is burned, it produces a dense black smoke and numerous burning particles so as to be visible by day or by night for many miles inclear weather. In an effort to reduce the sparks produced, screens have been; used, but the screens break up large particles into small pieces which may pass through the screen, and are therefore inelfective. Similarly, water sprays in stacks have been employed to extinguish burning particles. However, if sufiicient water was employed to extinguish large particles it entered the incinerator and interfered with combustion of the refuse and produced rapid corrosion of the metal surfaces. The several difficulties outlined above were effectively overcome by the spark arrester herein described, without detrimental effects on combustion or on the useful life of equipment.

The spark arrester, while highly effective on shipboard incinerators, is also useful for arresting. sparks on equipment of other types, such as city incinerators, locomotive, and saw mill boiler stacks. The unit efliectively traps and extinguishes large burning particles inan enlarged compartmenthaving a water-filled lower section and a baflie which reverses the direction of flow within the chamber. The gases and small particles leaving the chamber are subjected to an atomized spray of water which extinguishes any remaining particles. A second chamber at the exhaust end of the stack materially prevents the escape of the water spray and reduces the quantity of water required by' the spark arrester.

It is an object of the present invention to provide a spark arrester which will eliminate flying sparks and not detrimentally affect the operation of the combustion equipment.

It is also an object of the present invention to provide a spark arrester which requires small quantities of water for its operation.

It is a further object of the present invention to provide a spark arrested which extinguishes burning particles by separating them from the exhaust gases.

It is a still further object of the present invention to provide a spark arrester which extinguishes burning particles by separation from the larger particles from the exhaust gases and extinguishing the smaller particles by means of a fine water spray.

Other objects and advantages of the present invention will be made apparent by reference to the following description and to the appended drawings in which- Fig. 1 is a perspective view of the apparatus;

Fig. 2 is a section view taken on line 22 of Fig. 1; and

Fig. 3 is a detail view of the nozzle of the present invention.

2,736,541 Patented Feb. 28, 1956 Referring now to Fig. 1, the stack 11 from the incinerator (not. shown) carries the smoke and suspended particles produced in burning garbage and refuse into the chamber 14'. The stack 11 may bev inclined if desired or may be horizontal, but should terminate in a vertical direction within the chamber. The vertical direction of the stack 11 in the drawings is illustrative of one type of installation, although it will be apparent that the direction of. the stack may be readily changed to suit a particular installation.

The chamber 14 is provided with an access door 15 to facilitate cleaning and inspection of the unit. The door 15 may be hinged to the chamber as shown or may be made sliding or removable as desired. At the upper end, the chamber 14 is reduced in diameter to connect through plate 28 with a tube 30 having a diameter approximately equal to that of the stack 11. The tube 30 is equipped with an access door 32 which is attached in a manner similar to the door 15, and extends upward from the chamber 14 for a distance suflicient to rise above surrounding structures so as to provide an adequate draft and provide a compartment where smoke and suspended particles may intermix with the water spray.

The upper end of'the tube 30 is expanded into the cap 56 which has a diameter substantially equal to that of the chamber 14 and is provided with a bafi l'e 55 having a diameter larger than that of the tube 30 to prevent the entrance of rain and prevent the escape of an excessive amount of'water spray.

The stack. 11 extends into the chamber 14 for a considerable distance as shown in Fig. 2, and the junction between the chamber and the stack is sealed by a suitable means, such as welding, to be water-tight. A drain pipe 22 extends above the bottom and into the chamber 14 a sufficient distance to maintain a desired water level and an emergency overflow pipe 20 is provided in the event the drain pipe 22' becomes clogged. A screen 21 of wire mesh or expanded metal is wastened between the outer wall of the stack 11 and the inner wall of the chamber 14 to prevent trash from entering the drain pipe 22 and the overflow pipe 20 and clogging them and an additional screw plug 16 is also provided to drain the water from the chamber 14 when cleaning the residue from the bottom of the chamber. The bottom of the chamber 14. is kept filled with water emitted from the nozzle 35 and the water supply pipe 37.

A baffle 24, including a downward projection 26 at its center and having a' diameter considerably smaller than the. chamber 14 and considerably larger than the stack 11 is coaxially secured in the upper part of the chamber so as to cause the products of. combustion to reverse their direction of travel. The design of the baffle 24 is largely a matter of choice and may be composed of a double involute surface or a double conical surface as shown. The baffle 24 may be secured within the chamber 14 by any convenient means, such as the struts 27 welded to the wall of chamber 14 and the bafile 24.

The upper end of the chamber 14 is sealed to the lower end of the tube 30 by means of the conical section 28. The nozzle 35 is mounted approximately coaxially with the tube 30 and adjacent the door 32, and contains a number of very small holes which form sprays intersecting each other. The nozzle 35 is similar to the fog nozzle used in firefighting equipment, and produces very finely divided particles which effectively cover a considerable volume with a small amount of water, and is shown in Fig. 3 of the drawings.

The water supply pipe 37 may be used to secure the nozzle 35 within the tube 30, or other mounting methods may be employed. As illustrated herein, the water supply pipe is fastened to the tube 30 by means of the collar 38 or by means of welding. The water supply pipe 37 is bent to support the nozzle in its correct position and to clear the chamber 14. The water supply to the nozzle is controlled by means of the valve 40 between the water main 42 and the water supply pipe 37.

The pipe 4-4 is connected to the drain pipe 22 and through the valve 45 to the water main 42 to permit the operator to flush, after closing the valve 19, the drain pipe obstructed by residue.

The tube 30 extends into the cap and the cap is fastened to the tube by means of the conical funnel 52. A plurality of openings 53 are provided in the tube 30 adjacent the funnel 52 to allow water and particles to escape therethrough. The bafile 55 is similar to the baffie 24 and reverses the direction of flow of the gases so as to remove moisture and particles remaining in the gases by separating them into the cavity between the cap 50 and the tube 30. After passing the baflle 55, the gases which are now free from burning particles escape into the atmosphere.

The baflle 55 may be mounted in the cap by any convenient means, the struts 56 being merely illustrative.

The operation of the spark arrester is as follows: The products of combustion from an incinerator or boiler move up the stack 11 into the chamber 14 and strike the bafile 24- which reverses their direction. At the same time, the velocity of the gases project most of the solid matter carried by the gases into the lower portion of the chamber where they remain. Because the bottom of the chamber is covered with water, the solid particles are wetted, retained and any fire is extinguished.

The gases which pass around the baffle 24 are subjected to the fog spray from the nozzle 35 in the tube 34) which extinguishes any remaining burning particles in the gases. Such particles must be small and light to be carried by the gases through the chamber 14, and are therefore easily extinguished with a moderate amount of water.

The cap 50 separates most of the remaining solid particles and droplets of water from the gases, after which they pass out into the atmosphere. It will be apparent that the smoke will be considerably less dense because the suspended particles are removed and the gases are considerably washed by the water spray. Furthermore, no burning particles remain in the smoke.

To operate the spark arrester, the operator opens the drain valve 19 and then opens valve 40 to admit water to the nozzle. Water collecting on the inside of the tube 30 is conducted to the chamber 14 but is prevented from entering the stack 11 by the bafile 24, and fills the lower portion of the chamber 14 up to the opening of the drain pipe 20 and overflows through the drain pipe 20.

After the combustion has been completed, the operator closes valve in. The inside of the chamber 14- need not be cleaned after each use, but should be cleaned frequently. Cleaning the chamber is accomplished by opening the door 15 and scraping out the residue. Also, in the event that the drain pipe 22 becomes clogged, closing valve 19 and opening valve 45 will force the clogged matter free.

It will be readily apparent that many changes and modifications of the device herein described are possible. The stack 11 may be horizontal rather than vertical, and the shape of. the bafiles may be changed. The propertions or the structure may be change to suit the operating conditions of the installation.

The device herein described may be manufactured and used by or for the Government of the United States for Governmental purposes without the payment of any r alty therefore or thereon.

What is claimed is:

in a spark arrester for exhaust gases and particles from a smokestack, a tubular chamber having a diameter considerably larger than the diameter of said stack surrounding the end of said stack and in water-tight Contact therewith, stack extending into said chamber, a conical bat? ha in; an inverted downwardly projecting tip mounted within said chamber coaxially with and above the end of said sta k to present a continuous surface to the gases and particles emerging from said stack thereby to reverse the direction of movement of said exhaust gases and particles entering said chamber, means for maintaining water in the lower section of said chamber about the extension 0t said stack at a predetermined level thereby to separate and quench the larger solid particles which strike the surface of said water, a vertical exhaust tube having a diameter considerably smaller than said chamber extent.- ing from the end of said chamber housing the baflle, said exhaust tube having a series of slots on the extended end of, means including a fog spray nozzle mounted coaxially of said exhaust tube for spraying a finely divided spray of water therein to extinguish sir-taller parii' cles, said water and smaller particles falling about said bathe into the water in the lower section or" said chamber, a cap having a diameter cons; stably larger than said exhaust tube mounted on the slotted end or" said exhaust tube, said exhaust tube extending into said cap, and a second conical baille having an inverted downwardly projecting tip mounted in said cap coaxially with and above the end of said exhaust tube to prevent rain or other mospheric condensate from falling into said exhaust tube other than through the slots in said exhaust tube, said exhaust gases passing about Said batfic into said atmosphere.

References Cited in the file of this patent UNITED STATES PATENTS 

